Commercial plant growers use a variety of systems for the watering and feeding of plants. Overhead spraying, in which the sprayed water can contain nutrients for the plants, is widely used. In such systems, the spraying is generally controlled manually or by timers. Such systems necessarily wet the foliage of the plants, which, in turn, promotes the growth of undesired molds and fungi. In addition, overhead spraying is wasteful, since sufficient water must be used to both wet the foliage and saturate the soil beneath the foliage.
In view of the drawbacks of overhead spraying, systems have previously been developed which water the growing plants from the bottom. These systems generally involve periodic flooding of a tray of pots or continuous immersion of growing pots in a layer of water.